Let-back mechanism for looms



Nov. 1, 1927. I 1,647,234

A. J. LA CHAPELLE LET-BACK MECHANISM FOR LOOMS Filed Oct. 27, 1925 3 Shaw s-Sheet 1 Fig. 1.

'lnvenior Adeiard J. LaChapeHe A. J. LA CHAPELLE 'LET- BAQK MECHANISM FOR LOOMS Ncvo 1, 1927.

Filed Oct. 27 L935 3 Sheets-Sheet 2 Invenior. Adekzrd J. LcJChclpe WWW/ Nov. 1 1927.

A. J. LA CHAPELLE LET- BACK MECHANISM FOR LOOMS Filed Oct. 27, 1926 5 Sheets-Sheet 3 Inx/enfor. Adelord J. Lq Chop elle WMMW AT Tys Nov. 1,1927.

UNITED STATES PATENT. OFFICE.

ADELARD 3'. LA CHAPELLE, OF NEW BEDFORD, MASSACHUSETTS, ASSIGNOR TO DRAPER CORPORATION, OF HOPEDALE, MASSACHUSETTS, A CORPORATION 7 OF MAINE.

LET-BACK MECHANISM FOR LOOMS.

Application filed October 27, 1926. Serial No. 144,598.

This invention relates to looms provided with the usual cloth roll take-up mechanism and with positively driven actuating means for this mechanism and has for its principal object to provide pattern-controlled means for disconnecting this actuating means from the take-up roll mechanism, together with means operated by the pattern-controlled means acting when disconnection takes place once to lock the take-up roll mechanism against let-back either completely or to a predetermined extent. This enables a massed or corded efiect to be produced at regular intervals transversely of the cloth being woven. This is particularly useful in defining with accuracy longitudinal sections of the cloth and may also be of use in producing certain pattern effects.

The invention thus by. preventing, or determining with accuracy the amount of, letback under the control of the pattern mechanism enables the masses or cords of weft thus formed to be positioned accurately longitudinally of the clothand to be all of the same character.

In the case of looms provided with mechanism for automatically replenishing the.

weft or filling upon the breakagethereof or upon complete or partial exhaustion thereof, let-back mechanism is usuallyprovided to let back the clothroll take-upmechanism when replenishment takes place and thus to prevent thin places. The present invention does not interfere with such action of the usual let-back mechanism,v but preferably makes use of part of this usual mechanism when employed in this type of loom.

These and other objects and features of the invention will appear more fully in the accompanying description and drawings andwill be particularly pointed out in the claims.

The drawings illustrate so much of an automatic weft replenishing loom provided with a suitable pattern mechanism as is necessary to an understanding of the preferred form of the invention when embodied therein, but it will be understood that the invention is applicable to various types of looms.

In the drawings:

Fig. 1 is a front elevation of the'left-hand portion of a loom with a preferred form of the present invention embodied therein.

Fig. 2 is a side elevation of a portion ofthe loom with many of the parts broken away and partially in vertical cross section.

Fig. 3 is a view indetail much enlarged similar to a portion of Fig. 2, but with the locking pawl shown in looking position.

Fig. 4 is a view similar to Fig. 3 looking at the opposite side of the construction there- 111 shown.

As the general construction and operation'of a loom of the type illustrated and of cloth roll take-up mechanism of the type illustrated is well known and familiar to those skilled in the art, it will only be necessary to describe in detail those parts immediately concerned with an embodiment of the preferred form of the present invention.

The side frame 1 of the loom supports-at the top the usual breast beam 2 and at the bottom a girder 8, bothofwhich extend across to the opposite sideframe, not shown. An intermediate vertical frame member 4 is mounted on the girder 3 and extends up to. the breast beam.

The cloth as it is woven passes around a take-up or sand roll 5 journalled in the 100m frame and then winds up on a roll, not shown, in the usual manner. This take-up roll 5 is driven from a pinion 6 through a train of gearing 7. The pinion 6 is integral with or secured to a ratchet wheel 8 and these two elements are mounted on the shaft 9, which is journalled in a bracket 10 secured to theloom frame 1. The shaft 9 is provided at its outer end with a worm Wheel 11 engaging a worm 12 on a shaft 13, which shaft is continuously and positively driven through any suitable means during the ope eration of the loom. It will thus be seen that the take-up roll mechanism is thus continuously and positively actuated.

.A toothed clutch is provided on the shaft 9. One element 14 of this clutch is secured to or integral with the pinion 6, while the other element 15 is keyed at 16 to the shaft 9 so as to slide longitudinally upon, but to rotate with, the shaft, and is held in clutching engagement with the first element by the helical Spring 17.

The clutch' element 15 is moved to dis connecting position by a yoke 18 having studs 19 engaging I the shouldered face of the element 15. This yoke is pivotally mounted on a stud 20 and is. provided with a lateral arm 21. A link 22, the lower end. of which is shown, is operated by a connection with the weft replenishing mechanism. When weft replenishment takes place, the

link 22 moves downwardly, rocking the yoke 18 and disconnecting the clutch, thus allowing the pinion 6 and ratchet wheel 8 and the train of mechanism therefrom to the take-up roll 5 to let back. The amount of let-back which takes place under these circumstances is controlled by the detent pawls 23 and 2%. These pawls are pivoted at on a pawl carrier 26 journalled on the shaft 9 and provided with a weighted extension :27 which tends to carry the detent pawls to the left, viewing Fig. 1. During the normal operation of the take-up mechanism, these detent pawls ride over the teeth of the ratchet wheel and the pawl carrier 26 moves to a position where the stud 28 projecting therefrom engages a pin 29 adjustably positioned transversely of the arcuate slot 30 in a bracket 31 bolted at to the frame mem her 4. When, therefore, at the time of weft replenishment the clutch is disconnected and let-back takes place, the amount of let-back is determined by the distance from the pin 29 to the right-hand end of the arcuate slot 30, viewing Fig. 4.

All of the foregoing is a generally old type of mechanism and with it the present invention is not concerned other than to utilize in the preferred embodiment thereof a portion of this mechanism.

In the present invention a lever is mounted near the bottom of the loom frame. This lever comprises a fulcrum shaft journalled in vertically adjustable bearings, one of which is shown as a bracket adjustably secured by means of the bolt 85 passing through the vertical slot 36 in the side frame 1. The shorter arm 37 of this lever is rigidly mounted on the fulcrum shaft 38 and projects forwardly thereof. The longer arm of this lever is formed in two parts. One part 38 is rigidly secured to the fulcrum shaft 33 and provided with an arcuate slot 39. The other part to is pivoted at 11 on the part 38 and provided with a bolt 1-2 engaging the arcuate slot 39. Thus the part 40 is adjustable angularly and relatively with respect to the shorter part. This two-part arm of the lever projects rearwardly and at its rear end is provided with a plurality of apertures 43, either one of which may be engaged with a connection extending upwardly and under the control of a suitable pattern mechanism, such, for example, as a dobby mechanism generally indicated at 44. The connection between the lever and the pattern mechanism is preferably of ayielding nature. As shown, a frame 15 is connected by a rod'4e6 to the pattern mechanism. 'In this frame is slidably mounted a rod 47 connected at its lower end by a link 48 with one of the apertures 43. A helical spring 49 is mounted within the frame on the rod 47 and engages at its lower end the frame and at its upper end a collar 50 ad j ustably secured to the rod 47. Consequently it will be seen that when the pattern mechanism acts to pull the longer arm of the lever upwardly, this connection will yield if the upward movement of the lever is limited. An adjustable stop 51 is provided for thus limiting the upward movement of the lever arm and is shown as adjustably secured by a bolt 52 in a slot in the loom side frame 1. A carrier lever 5 1 is fulcrumed at 55 on an extension 56 depending from the bracket ill and this carrier lever supports the stud 20 on which the yoke 18 is pivoted. A curved depending arm 57 of the carrier lever extends downwardly and rests against the side of the lever arm 37 so that normally the parts stand in the position shown in full lines in Figs. 1 and 2. The yoke 18 may rock to the left, viewing Fig. 1, on the stud 20 with respect to the carrier lever 541, but not to the right. Consequently if the arm 57 of the carrier lever be swung to the right, viewii'ig Fig. 1, the yoke 18 will be swung bodily to the left and will eii'ect the dis connecting n'iovement of the clutch. Thus it will be seen that when the patterncontrolled means acts to pull up on the longer arm 40 of the lever fulcrumed at 33, the shorter arm 37 will move downwardly against the curved surface of the depending arm 57 of the carrier lever and move the clutch to disconnecting position. A spring 58 connected to the lever arm 37 and to the bracket extension 56 acts to hold the lever arm 37 in normal or full line position as shown in Figs. 1 and 2. Butw en this pattern-controlled means thus acts to effect the disconnection of the clutch, it is in'iperative for the purposes of this invention that the take-up roll mechanism shall he positivelv locked against let-back either entirely or a definite and predetermined extent: This is secured in the present invci'iticn by a means which itself is o crified by the battern-controlled means. i For this purpose a locking oawl It justably pivoted on the lever arm part A bracket 60 is adjustably secured by bolts 61 longitudinally of this part ft) sun the pivot pin 62 of the locking pawl adjustably mounted in the slot 63 of the bracket 80. The nose 6% of the loci .ng pa.

extends opposite the teeth of he ratcl wheel 8 and rests and slides in a uice she n as a bracket 65 adjustably moi: l i

of a bolt 66 passing through a slot bracket and secured to the .cket By means of the various adjustments vided, such as the bolt 35 in the slot the bracket 60 on the part 10, the pivot 62 in the slot 63, the bolt 66 in the slot 67. and the bolt 52 in the slot 53, the nose 6 1 of the locking pawl may readilybe positioned so as to be seated firmly against or in any predetermined positionin front of a tooth onthe ratchet wheel 8 when the pattern-controlled means has acted to rock the lever arm'37 to effect the disconnection of the clutch, thus either absolutely preventing let-back or limiting the let-back to a definite and predetermined extent. Consequently as the weaving operation proceeds with the clutch disconnected, the wefts are beaten in in a bunch or cord, and when, under the control of the pattern means, the lever arm 37 rocks upwardly and. the spring 17 connects the clutch, the toothed members of the clutch engage accurately'and the take-up mechanism resumes its operation without any further let-back taking place.

The pattern-controlled means thus acts to effect the disconnection and connection of the clutch accurately and positively at such intervals as may be determined by the pattern means and at the same time the pattern-controlled means 7 locks the take-up mechanism against let-back as required. It will also be seen that this takes place without any interference with the letting back of the take-up roll mechanism to the extent required upon weft replenishment.

A hand pawl arm 68 is loosely mounted V on the shaft 9 provided with the depending handle 69 and with the tooth 70 so that by raising this arm on the shaft 9 and bringing the tooth 70 into engagement with the ratchet wheel 8, the take-up roll may be r0- tat-ed manually when desired, but this feature forms no part of the present invention.

Having thus described the invention, what is claimed as new, and desired to be secured by Letters Patent, is:

l. A loom comprising a clothtake-up roll mechanism, continuously and positively driven actuating means therefor, patterncontrolled means for disconnecting and connecting said'actuating means and said take up roll mechanism, and means operated by said pattern-controlled means to lock the take-up roll mechanism upon said disconnection against a degree of let-back determined by said operated means. 7

2. A loom comprising a cloth take-up roll mechanism including a ratchet wheel, continuously and positively driven actuating means for said mechanism, pattern-controlled means for CliSCODIlGCtiIlg and connecting said actuating means and said take-up roll mechanism, and a locking pawl connected with said pattern-controlled means and moved thereby into a predetermined position with respect to the ratchet wheel and acting to lock the take-up roll mechaloom frame acting when rocked under the control of the pattern mechanism to effect the disconnection of said actuating means and said take-up roll mechanism, and a locking pawl connected with said lever and moved thereby into a predetermined p'osi tion with respect to the ratchet wheel and acting to lock the take-up roll mechanism upon said disconnection against let-back be yond a predetermined extent.

5. A loom comprising the construction defined in claim 4 in which the locking pawl is pivoted on the lever and in which a guide for the pawl nose is mounted on the loom frame to guide the pawl into the required position with respect to the ratchet wheel.

6. A loom comprising the construction defined in claim 4 in which that arm of the lever to Which the locking pawl is connected 1s in two parts and in which means are provided for relatively and angularly adjusting the said lever parts. I

7. A loom comprising the construct-ion defined in, claim 4 in which means are provided for mounting the fulcrum of the lever on the loom frame and adjusting it relatively thereto, thus to adjust the cooperative relation of the locking pawl and ratchet wheel.

8. A loom comprising the construction defined in claim 4 in which the pattern-controlled means controls the movement of the lever through a yielding connection, enabling a yield in the connections to take place after the pawl is seated against the teeth of the ratchet wheel. I

9. -A loom comprising the construction defined in claim 2, in. Which the pattern-controlled means acts, in effecting the movement of the locking pawl as therein set forth, through a yielding connection thus enabling a yield in the connections to take place after the pawl is in looking position.

In testimony whereof, I have signed my name to this specification.

ADELARD J. LA CHAPELLE. 

